Impact of Legacy Phosphorus on Lake Erie Blooms
A sampling site in western Lake Erie showing typical conditions on May 23, 2023 (left) and sediment resuspension after two days of strong winds, observed on May 26, 2023 (right). These events release phosphorus into the water column.
Legacy Phosphorus and its Impact on Lake Erie Harmful Algal Blooms
Funding: NASA Remote Sensing of Water Quality
Western Lake Erie water quality is severely degraded by recurring harmful algal blooms every summer, with varying degrees of severity and toxicity. The primary driver of these events is excess phosphorus from extensive agriculture occurring in Lake Erie watersheds. However, this driver alone does not adequately predict the size, severity, and duration of harmful algal blooms in western Lake Erie. A key missing component is an in-depth understanding of internal phosphorus cycling; western Lake Erie sediment, rich in legacy phosphorus, is resuspended in the water column frequently. The frequency and availability of this legacy phosphorus to the aquatic ecosystem is poorly constrained, both in Lake Erie and other similarly impacted systems.
This project aims to improve our understanding of internal phosphorus cycling in western Lake Erie through a suite of optical, chemical, isotopic, and sediment in situ observations. Using this data, we seek to characterize how sediment and colored dissolved organic matter, alongside classifications of optical variability in Lake Erie, can serve as predictors of internal phosphorus cycling from satellite observations. We expect this information to be critical in understanding interannual variability in harmful algal bloom dynamics in Lake Erie's western basin that are currently not well predicted using data on riverine phosphorus loading alone. This work will extend past Lake Erie, to inform how we can constrain the impacts of legacy nutrient loading in space and time.
